小编Roa*_*nmo的帖子

我最近偶然发现了这条消息，我很确定这个构造函数在 18.0.0 之前的版本中没有被弃用，但我也找不到任何地方也找不到这个构造函数已被弃用的信息。

我们应该使用什么来代替，有没有另一种方法来创建一个locationRequest？

我有一个使用应用程序内更新的 Android 应用程序。以 android 14 (API 34) 为目标后，应用程序将因以下错误而无法启动：

FATAL EXCEPTION: main\nProcess: no.norva24.mslam, PID: 8281\njava.lang.RuntimeException: Unable to start activity\nComponentInfo{no.norva24.mslam/no.norva24.mslam.ui.activities.MainActivity}: java.lang.SecurityException: no.norva24.mslam: One\nof RECEIVER_EXPORTED or RECEIVER_NOT_EXPORTED should be specified when a receiver isn't being registered\nexclusively for system broadcasts\n    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3782)\n    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3922)\n    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:103)\n    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:139)\n    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:96)\n    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2443)\n    at android.os.Handler.dispatchMessage(Handler.java:106)\n    at android.os.Looper.loopOnce(Looper.java:205)\n    at android.os.Looper.loop(Looper.java:294)\n    at android.app.ActivityThread.main(ActivityThread.java:8176)\n    at java.lang.reflect.Method.invoke(Native Method)\n    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:552)\n    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:971)\nCaused by: java.lang.SecurityException: no.norva24.mslam: One of RECEIVER_EXPORTED or RECEIVER_NOT_EXPORTED\nshould be specified when a receiver isn't being registered …

以下FetchAddressIntentService实现IntentService（在 kotlin 中）：

class FetchAddressIntentService  //Constructor of this service
    : IntentService(INTENTTAG) {
    //Receiver where results are forwarded from this service
    protected var resultReceiver: ResultReceiver? = null

    private val TAG by lazy { this::class.java.simpleName }

    //Intent Service handler
    override fun onHandleIntent(intent: Intent?) { //Errormessages
        var errorMessage = ""
        if (intent != null) {
            resultReceiver =
                intent.getParcelableExtra(RECEIVER)
        }
        //Checks if receiver was properly registered
        if (resultReceiver == null) {
            Log.wtf(
                TAG,
                "No reciever received. There is nowhere to …

我试图在我的应用程序中使用 Flow 将我的 Paging 2 实现转换为 Paging 3，但受到“Channel was closed”异常的困扰。该应用程序运行良好，但在一段时间后崩溃（从几秒钟到几分钟）。它从网络加载数据，这可能很慢。使用 Room 作为内部数据库。模拟器上的崩溃比真实设备上的要频繁得多。

我不熟悉 Flow，我应该注意 Flow 系统中是否有任何已知的罪魁祸首？

有没有其他人在使用 androidx 的 Paging 3 时遇到过类似的情况？

因此，如果这是一个已知问题（可能有明显的修复方法），请给我一个提示；与否，我可能会发布 Paging 3 代码部分（这将需要一些时间）。

我的异常如下所示：

2020-06-29 09:23:59.929 28295-28295/no.rogo.emptyfuel E/AndroidRuntime: FATAL EXCEPTION: main
    Process: no.rogo.emptyfuel, PID: 28295
    kotlinx.coroutines.channels.ClosedSendChannelException: Channel was closed
        at kotlinx.coroutines.channels.Closed.getSendException(AbstractChannel.kt:1035)
        at kotlinx.coroutines.channels.AbstractSendChannel.helpCloseAndResumeWithSendException(AbstractChannel.kt:206)
        at kotlinx.coroutines.channels.AbstractSendChannel.access$helpCloseAndResumeWithSendException(AbstractChannel.kt:19)
        at kotlinx.coroutines.channels.AbstractSendChannel.sendSuspend(AbstractChannel.kt:196)
        at kotlinx.coroutines.channels.AbstractSendChannel.send(AbstractChannel.kt:135)
        at kotlinx.coroutines.channels.ChannelCoroutine.send$suspendImpl(Unknown Source:2)
        at kotlinx.coroutines.channels.ChannelCoroutine.send(Unknown Source:0)
        at androidx.paging.PageFetcherSnapshot$pageEventFlow$1$2$invokeSuspend$$inlined$collect$1.emit(Collect.kt:137)
        at kotlinx.coroutines.flow.FlowKt__ChannelsKt.emitAllImpl$FlowKt__ChannelsKt(Channels.kt:58)
        at kotlinx.coroutines.flow.FlowKt__ChannelsKt$emitAllImpl$1.invokeSuspend(Unknown Source:11)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:56)
        at kotlinx.coroutines.EventLoop.processUnconfinedEvent(EventLoop.common.kt:69)
        at kotlinx.coroutines.DispatchedTaskKt.resumeUnconfined(DispatchedTask.kt:184)
        at kotlinx.coroutines.DispatchedTaskKt.dispatch(DispatchedTask.kt:108)
        at kotlinx.coroutines.CancellableContinuationImpl.dispatchResume(CancellableContinuationImpl.kt:308)
        at kotlinx.coroutines.CancellableContinuationImpl.completeResume(CancellableContinuationImpl.kt:395)
        at …

致力于jetpackcompose在 Android Studio 4.0 Canary 中了解 android 。

我有一个简单的jetpackcompose设置，VerticalScroller如下所示：

@Composable
fun MyScreenContent(appState: AppState = AppState())
{

    FlexColumn{


       flexible(flex = 1f){
           VerticalScroller {
             Column {
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
                CardDemo()
            }
        }
    }
 }
}

它完美地滚动，但我想要一个scrollindicator显示我的列表滚动了多远，我如何打开它，找不到任何ScrollIndicator（即）组件来包含。

参考 到RecyclerView在非可组合设置（XML），其中scrollindicator是可见的：

            <androidx.recyclerview.widget.RecyclerView
                android:id="@+id/station_list"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:background="@color/recyclerview_background_color"
                android:clipChildren="true"
                android:clipToPadding="false"
                android:fadeScrollbars="false"
                android:paddingLeft="0dp"
                android:paddingRight="0dp"
                android:scrollbarSize="4dp"
                android:scrollbarThumbVertical="@color/colorPrimary"   <---
                android:scrollbars="vertical"                          <--- …

我有以下场景：

芯片定义：

<chip xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    app:chipIcon="@drawable/ic_baseline_house_24"
    android:text="@string/chips_holder"
    app:closeIconEnabled="true"
    />

包含 TextInputTeditText 的 xml 部分：

...
<com.google.android.material.textfield.TextInputLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox.Dense"
    android:enabled="true"
    android:hint="Gallery Selections"
    android:layout_weight="1">
    <com.google.android.material.textfield.TextInputEditText
        android:id="@+id/fragment_gallery_text_input_edit_text_selections"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:clickable="false"
        android:cursorVisible="false"
        android:focusable="false"
        android:focusableInTouchMode="false" />
</com.google.android.material.textfield.TextInputLayout>
...

房间 liveData 结果观察器，提供来自一组变量的数据：

...
liveDataFilterGallery?.observe(
    viewLifecycleOwner
){filterGalleryResult->
    filterGalleryResult?.let { safeFilterGalleryResult->
        safeFilterGalleryResult.apply {
            val prefixes = arrayOf(
                "Site No",
                "Farm No",
                "Site Id",
                "Assignment Id",
                "Category",
                "Time Stamp")
            fragmentGalleryTextInputEditTextSelections.setText(
                (if(siteNo.isNullOrEmpty()) "" else "${prefixes[0]} = '$siteNo';") +
                (if(farmNo.isNullOrEmpty()) "" else "${prefixes[1]} = '$farmNo';") +
                (if(siteId.isNullOrEmpty()) "" else "${prefixes[2]} …